• The Journal of Engineering Geology
• /
• v.30 no.4
• /
• pp.589-602
• /
• 2020

As can be seen in many earthquakes, liquefaction causes differential settlement, which sometimes produces serious damages such as building destruction and ground subsidence. There are many possible active faults near the Busan city and the Yangsan, Dongrae, and Ilgwang faults among them pass through the city. The Busan city is also located within the influence of recent earthquakes, which occurred in the Gyeongju, Pohang, and Kumamoto (Japan). Along the wide fault valleys in the city, the Quaternary unconsolidated alluvial sediments are thickly accumulated, and the reclaimed lands with beach sediments are widely distributed in the coastal area. A large earthquake near or in the Busan city is thus expected to cause major damage due to liquefaction in urban areas. This study conducted an assessment of the liquefaction hazard according to seismic recurrence intervals across the Busan city. As a result, although there are slight differences in degree depending on seismic recurrence intervals, it is predicted that the liquefaction potential is very high in the areas of the Nakdonggang Estuary, Busan Bay, Suyeong Bay, and Songjeong Station. In addition, it is shown that the shorter the seismic recurrence interval, the greater difference the liquefaction potential depending on site periods.

• Journal of the Korean earth science society
• /
• v.42 no.1
• /
• pp.76-87
• /
• 2021

In this study, temporal trend of researches in earthquake with groundwater level, water quality, radon, remote sensing, electrical resistivity, gravity, and geomagnetism was searched from 2001 to 2020, using the journals indexed in Web of Science, and the number of articles published in international journals was counted in relation to the occurrences of earthquakes (≥Mw 5.0, ≥Mw 6.0, ≥Mw 7.0, ≥Mw 8.0, and ≥Mw 9.0). The number of articles shows an increasing trend over the studied period. This is explained by that studies on earthquake precursor and seismic monitoring becomes active in various fields with integrated data analysis through the development of remote sensing technology, progress of measurement equipment, and big data. According to Mann-Kendall and Sen's tests, gravity-related articles exhibit an increasing trend of 1.30 articles/yr, radon-related articles (0.60 articles/yr), groundwater-related articles (0.70 articles/yr), electrical resistivity-related articles (0.25 articles/yr), and remote-sensing-related articles (0.67 articles/yr). By cross-correlation analysis of the number of articles in each field with removing trend effect and the number of earthquakes of ≥Mw 5.0, ≥Mw 6.0, ≥Mw 7.0, ≥Mw 8.0, and ≥Mw 9.0, radon and remote sensing fields exhibit a high cross-correlation with a delay time of one year. In addition, large-scale earthquakes such as the 2004 and 2005 Sumatra earthquake, the 2008 Sichuan earthquake, the 2010 Haiti earthquake, and the 2010 Chile earthquake are estimated to be related with the increase in the number of articles in the corresponding periods.

• Industry Promotion Research
• /
• v.6 no.2
• /
• pp.55-62
• /
• 2021

The number of single-parent families in South Korea increased since 2000, related to a sharp rise in the divorce rate of 50s and an increase in male mortality rates among those aged 40s-50s. Middle-aged single mothers experience a critical period realizing self-actualization needs, while being in the middle adulthood from the lifespan developmental perspective. In this respect, it is significant to study self-actualization of middle-aged single mothers through guided imagery and music (GIM) in order to provide them with psychological support. This study was conducted from September 2018 to June 2020, and the GIM sessions were conducted at least 10 times. Four participants were selected among the middle-aged single mothers. The imagery experiences of participants in the GIM sessions were classified into four sub-elements: physicalness, emotion, memory, and sense. Within those sub-elements, eight semantic units were categorized into 46 elements. Finally, 152 semantic units were derived. Moreover, the self-actualization which participants experienced through GIM presented three archetypal images: shadow, persona, and the self. In the GIM sessions, experiences of putting their negative emotions associated with family into words and changing passive self-imagery into active one enabled participants to bring the shadow into their consciousness, there by recognizing their positive and bright internal self. Furthermore, participants could map that their current status as people marginalized by siblings and parents, enraged and holding double standards for others, was suppressed by their 'good daughter' and 'religious' personas. This realization lead them to realize and restore their persona. The use of GIM in the study allowed participants to elicit re-experiences of the negative events, while experiencing various imagery and music. This process helped participants achieve self-actualization.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.8
• /
• pp.193-202
• /
• 2021

HYBE Insight, opened in May 2021, is an exhibition space that visually displays and re-interprets the BTS Universe and its content. The space echoes the identity of BTS as an artist and the specificity of the cultural phenomenon they have generated. This study analyzes HYBE Insight's BTS exhibition by applying new museological theories and discourses. Based on a qualitative research methodology including literature review and observational method, the primary themes of the exhibition are follows: 1) a contextualized exhibition content presenting the identity of BTS and their music, 2) the role of the fandom Army's participation in (re) producing BTS content related to the characteristic of popular music museums, 3) the elements of convergence art and its contemporary implication, 4) and the illumination of cultural value in popular music museum management. As the pivotal theory of new museology suggests, investigating a specific exhibition based on each context it has created is significant. However, those studies, including exhibitions related to popular music/artists, were mostly developed in Western nations. In this respect, HYBE Insight's BTS exhibition provides considerable room to explore. In addition to the recent research on BTS, such as their convergent artistry, socio-cultural influence, the role of Army, and the characteristics of HYBE's content management, this article aims to contribute to the multifaceted research by scrutinizing the BTS exhibition content from the new museology perspective.

• Journal of Korean Elementary Science Education
• /
• v.41 no.2
• /
• pp.186-198
• /
• 2022

With the science curriculum about to be revised in 2022, this study aimed to guide curriculum revision by addressing suggested approaches to the electromagnetism education in elementary school science curriculum. The core concepts of electromagnetism are "electric field" and "magnetic field" as a medium of force, but the current curriculum does not properly describe the core concepts of electromagnetism. Mechanics and electromagnetism should be linked in elementary schools to form science curriculum based on core concepts to solve this problem. Additionally, the nine aspects of technology extracted in this study offer various educational contexts to match the development of engineering technology based on electromagnetism. However, the current curriculum does not comprise these various contexts and focuses on the limited content of electric circuits using light bulbs. Therefore, it is necessary to expand the scope of the curriculum to better mirror real-life technology. Through the use of more diverse materials and contexts, the scope and level of STS education as well as conceptual learning could be expanded. Finally, in the case of electric circuit learning, various issues such as difficulty in connecting electric circuits and electric field concepts, representativeness of electric circuit, students' learning difficulty, and phenomena-oriented learning should be considered.

• Economic and Environmental Geology
• /
• v.55 no.5
• /
• pp.497-510
• /
• 2022

Monthly monitoring, 3D scan survey, and electrical resistivity survey were conducted from January 2018 to August 2022 to identify the cause of rockfall occurring in Daljeon-ri Columnar Joint (Natural Monument No. 415), Pohang. A total of 3,231 rocks fell from the columnar joint over the past 5 years, and 1,521 (47%) of the falling rocks were below 20 cm in length, 978 (30.3%) of 20-30 cm, and 732 (22.7%) of rocks over 30 cm. While the number of rockfalls by year has decreased since 2018, the frequency of rockfalls bigger than 30 cm tends to increase. Large-scale rockfalls occurred mainly during the thawing season (March-April) and the rainy season (June-July), and the analysis of the relationship between cumulative rainfall and rockfall occurrence showed that cumulative rainfall for 3 to 4 days is also closely related to the occurrence of rockfall. Smectite and illite, which are expansible clay minerals, were observed in XRD analysis of the slope material (filling minerals) in the columnar joint, and the presence of a fault fracture zone was confirmed in the electrical resistivity survey. In addition, the confirmed fault fracture zone and the maximum erosion point analyzed through 3D precision measurement coincided with the main rockfall occurrence point observed by the BTC-6PXD camera. Therefore, the main cause of rockfall at Daljeon-ri columnar joint in Pohang is a combination of internal factors (development of fault fracture zones and joints, weathering of rocks, presence of expansive clay minerals) and external factors (precipitation, rapid thawing phenomenon), resulting in large-scale rockfall. Meanwhile, it was also confirmed that the Pohang-Gyeongju earthquake, which was continuously raised, was not the main cause.

• Geophysics and Geophysical Exploration
• /
• v.25 no.3
• /
• pp.120-128
• /
• 2022

There are 17,000 reservoir dams in Korea, of which more than 85% were built over 50 years ago. Old embankment dams are weakened by internal erosion and suffusion phenomena due to preferential leakage paths and this ongoing weakening can cause their failure. Therefore, early warning associated with leakage in an embankment dam is crucial to prevent its failure. An electrical resistivity survey is a non-destructive, real-time and in-situ technique for detecting the development of leakage zones and general conditions of embankment dams. Because of its advantages, the electrical resistivity survey is widely used for reservoir safety inspections. However, the electrical resistivity survey is still not officially included in the precise safety inspection of reservoir dams because it cannot present a quantitative index of dam safety. In this study, we propose a method for calculating the leak index according to the water content evaluated from the electrical resistivity survey and/or induced polarization survey. Particularly, by proposing a quantitative leak index calculation method from monitoring surveys and independent surveys, we provide a theoretical basis for including electrical resistivity and induced polarization surveys as components of the precise safety inspection of reservoirs dams.

• Journal of Korea Water Resources Association
• /
• v.56 no.9
• /
• pp.553-562
• /
• 2023

The Gobiobotia naktongensis is a species endemic to Korea, and it has recently been designated as a class I endangered species of freshwater fish. Naeseong Stream, one of the tributaries of the Nakdong River, where the Gobiobotia naktongensis was first discovered, provided an optimal habitat for the Gobiobotia naktongensis in the past with fine sand beds and riffle. Currently, due to the construction of Yeongju Dam and the excessive dredging of river channels by the local government, the riverbed armoring in the downstream area of the dam is undergoing rapid changes, and as a result, the habitat environment of the Gobiobotia naktongensis is deteriorating. In this study, the variations of the habitat suitability of the Gobiobotia naktongensis due to the change in the riverbed grain size of the Naeseong Stream were analyzed based on the WUA (weight usable area) using the physical habitat model, River2D. The study domain is the reach from Seoktap Bridge to Hoeryong Bridge downstream of Yeongju Dam. The change in riverbed grain size was analyzed using D50 acquired in 2010 and 2020, respectively. The substrate grain size of Naeseong Stream in 2020 was thicker than that in 2010, and the riverbed coarsening phenomenon was evident overall. As a result of the River2D analysis, the area in which the Gobiobotia naktongensis could inhabit was only about 0.75% in 2010 compared to the entire area of the flow, and even this decreased to 0.55% in 2020 due to riverbed armoring.

• Journal of Popular Narrative
• /
• v.25 no.2
• /
• pp.33-69
• /
• 2019

This thesis aims to reveal the meanings of SF as a genre in Korea. Most of the studies on the characteristics of SF novels in Korea have revealed the meanings of characteristic elements of SF, or peripherally reviewed the characteristics of works. However, these methodologies have a limitation, such as analysis through the existing methodologies, while overlooking the identity of SF texts with the characteristics as a genre. To clearly define the value of texts in the SF genre, an understanding of the customs and codes of the genre is first needed. Thus, this thesis aims to generally handle matters like the historical context in which Korean SF was accepted by Korean society, and the meanings and characteristics when they were created and built up relationships with readers. In addition to fully investigating SF as a popular narrative & genre narrative that has not been fully handled by academic discourses, this thesis aims to practically reconsider the present/future possibilities of SF, which is currently being reconsidered given that the scientific imagination is regarded as important in the 21^st century. This thesis considers the basic signification of Korean SF texts in academic discourses. Through this work, numerous Korean SF that have not been fully handled in the area of literature and cultural phenomena will be evaluated for their significance within the academic discourses, and also reviewed through diverse research afterwards. As a result, this work will be helpful for the development of discourse and the expansion of the Korean narrative area that has been diversely changed since the 21^st century.

• Elastomers and Composites
• /
• v.37 no.4
• /
• pp.244-257
• /
• 2002

A thermotropic liquid crystalline polymer(TLCP) which has flexible butylene/hexylene spacers in the main chain and a triad aromatic ester type mesogenic unit containing a naphthyl group was prepared by solution polycondensation. The in-situ composites based on poly(ethylene 2,6-naphthalate) (PEN) and a thermotropic liquid crystalline polymer(TLCP) were prepared and melt spun at different TLCP contents and different draw ratios to produce monofilaments. Blends of the TLCP with PEN were investigated in terms of thermal, mechanical properties and morphology. The TLCP synthesized showed nematic mesophasic behavior and its transition temperature to isotropic melt from mesophase was 249℃. The blends showed well dispersed TLCP phases in the PEN matrix without macroscopic phase separation. Inclusion of TLCP in the blends decreased the cold crystallization temperature of PEN in the blend, therefore, the TLCP acts as a nucleating agent in the blend and showed good interfacial adhesion between the dispersed LCP phases and PEN matrix with domain sizes 40~50 nm in diameter and well developed fibrillation in the monofilaments. The TLCP acted effectively as a reinforcing material in the PEN matrix at the 10wt% level, it led to an increase of initial modulus up to 270% and tensile strength by 235%, while the elongation rate increasing with higher draw ratios.